Wheel truing mechanism



R. E. FLAnl-:Rs T AL l2,187,229

Jan. 16, 1940.

WHEEL TRUING 'MECHANISM Filed Aug. 2e, 1957 4 sheets-sheetl 1 willi IFIIIL..

` Jan. 16, 1940.

WHEEL TRUING MEGHANISM Filed Aug. 26. 1957 4 Sheets-Sheet 2 R. E. FLANDERS ET A1.

WHEEL TRUING MECHANISM Jan. 16, 1940.

4 Sheets-Sheet 3 Filed Aug. 26, 1957 Jan.16,1940. R. E. FLANDES ET 2,187,229'

A WHEEL TRUING MECHANISM Filed Aug. 26, 1957 4 Sheets-Sheet 4 19M?! Jwf v rr d' Patented Jan. 16, 1940 PATENT OFFICE WHEEL TRUING MECHANISM Ralph E. Flanders and Lee M. Davis, Springileld, Vt., assignors to Jones & Lamson Machine Company, Springfield, Vt., a corporation of Vermont I Application August 26, 1937, Serial No. 160,956`

10 Claims.

'Ihis invention relates to mechanism for truing grinding wheels and has for an object to provide for ready adjustment of the motion of the truing devices so that the facesof the grinding wheel may be truedexactly to various angles.

A further object is to provide an improved mechanism for eifecting traverse ofthe truing tools along faces of the wheel.

A still further object is to provide a truing mechanism having the desired characteristics hereinbefore mentioned and which is particular- 1y suitable for truing the faces of wheels for grinding threads.

A further object is to provide means for facilitating the control of the speed of rotation of the grinding wheel in order to maintain the deaired surface cutting speed of the wheel as its diameter is reduced bis? Wear and truing.

For a more complete understanding of this invention, reference may be had to the accompanyim; drawings showing one embodiment thereof by way of example, in which Figure 1 is a fragmentary rear end elevation of a thread-grinding machineshowing a wheeltmaing mechanism embodying the invention.

Figure 2 is a fragmentary side elevation showing a portion of the mounting of the truingv mechanism.

Figure 3 is a transverse section through the truing mechanism on the line 3 3 of Figure 4.

Figure 4 is a detail longitudinal section on the 'line 4 4 of Figure 1.

Figure 5 is a horizontal section through the truing mechanism on the line 5 5 of Figure 6.

Figure 6 is asection on line M oi' Figure 5.

Figure 7 is a detail section on line 1--1 o! Figure 6.

Figure 8 is a detail section on line 8 9 of Figure 4.

Figure 9 is a front end elevation of the truing mechanism.

Figure 10 is a detail section Figure 6.

Figure 11 is an exploded perspective view of a truing device adjusting mechanism.

Figure 12 is a fragmentary front elevation of the machine showing arrangements for faci1i` tating adjustment of the grinding wheel speed in accordance with its decreasing diameter due to wear and truing. Y

Figures 13 and 14 are elevations to a larger scale of certain indicating plates shown in Figure 12.

Figure 15 is a wiring diagram ot the wheel driving motor control.

on line I0-I0 of 'I'he truing mechanism herein shown is illustrated as used in connection with a thread grinding machine of the general type shown in the Flanders Patent No. 1,739,753, granted December 17, 1929. The grinding wheel is shown at I 5 carried by a shaft 2 and journaled in aslidable frame portion 3, this portion 3 being so mounted as to be moved toward and from the work as illustrated in the Flanders patent. Upon the frame 3 which carries the grinding wheel is ar` lo ranged a wheel-truing mechanism which, as herein illustrated, comprises an angularly adjustable cylindrical casing 5 and an angularly xed portion 6. Thisixed portion 6 is guided for axial motion from and toward the wheel I as on a l5 guide bar 1, the part 6 being provided with a slotted lower end at 8 which slidably engages the bar l. This guide bar l is secured as by one or more screws 9 to a frame portion I0 movable toward and from the work with the frame portion 3. The casing 5 may be secured in its angularly adjusted relation to the part 6 as by means of the bolt and slot connections at I5 shown best in Figure 1 and a series of bolts I5a passing through the portion 6, outside of the casing 5 and threaded into a clamping segment II engaging an extension on a cover plate I2 secured to the end of the casing 5 as by screws I3. The two parts 5 and 6 together comprise a carriage for supporting the wheel-truing mechanism as will later be more specicallyl described, and this mechanism as a whole being supported on rollers I6.' is moved from and toward the axis of the grinding wheel in order to eiect traverse ofthe truing devices along the sidefaces of the wheel. It is also adjusted toward the Wheel as the wheel is trued, and this mechanism, with the adjusting for wheel truing, may be driven from the main drive mechanism of the machine, as shown in the Flanderslpatent hereinbefore mentioned. Portions of connections for eiecting this drive are shown in Figure 4, these comprising a shaft 20 journaled in bearings 2| and 22 of the main frame of the machine, the shaft 20A being provided with a driving gear 23 which may be driven from the main drive mechanism in` any suitable manner and at suitable times, as at a, limit of traverse between the grinding wheel and the work being ground. This shaft 20 has secured thereto a pinion 24 which meshes with a long gear 25 journaled on a shaft 26 secured in the frame portion Ill of the wheel slide. T'he long gear provides for driving connections from the shaft 20 throughout the range of motion of the wheel in feeding toward and retracting from with a gear 21 secured to a shaft 28. This shaft 28 is journaled at one end in a bearing 29 and toward its other end is threaded at 30 and has threaded engagement with a nut 300 secured in a wall member 3| shown as integral with the frame portion |0. Thus as the long gear is rotated, the gear 21 is also rotated and the shaft 28 is not only rotated but is given a lengthwise motion due to its threaded engagement with the nut 300. This threaded portion 300 extends through a double arcuate slot 32 in an annular guide member 33 forming part of the frame 3 which itself is rockably carried on a supporting cradle 34 formed on the Wheel slide so that the shaft 28 will not interfere with the proper angular adjustment of the easing 5 and of the Wheel head. As shown in Figure 1, this wheel head or frame 3 may be provided with lugs 36 through which are passed the pivots 31 for the threaded adjusting rods 39 which are provided with knurled adjusting nuts 39 by which the angular position-of the frame 3 and the central plane of the wheel may be adjustably xed. The lower ends of the rods 38 may be pivotally secured as at 40 to any convenient part of the wheel slide. The. rear end of the shaft 28 is provided with a suitable abutment 45 which determines the limit of inward motion of the truing mechanism toward the grinding wheel for any particular portion of the cycle of the truing mechanism. This abutment is arranged to be contacted by the inner end of an axially movable rod 50 carried by the angularly fixed member 6 and in alinement with the end of the shaft 28. In the inner end of rod 50 it is shown as supporting a ball 5| which directly engages the abutment 45, it being unnecessary that this rod 50 be rotated with the rotation of the shaft 28. The outer end of the rod 50 engages a ball at 52 supported in a socket at the lower end 53 of a lever 54 fulcrumed at 55 on the angularly fixed member 6. The upper end. of this lever 54 is provided with a socket 56 for the reception of a ball 560 for engagement by the outer end of a thrust rod 51 slidably mounted in the casing 5 and coaxial therewith, so that for any angularly adjusted position of the casing 5 the rod 51 will be in proper alinement with the lever 54. It will be evident that, by moving the rod 51 forwardly within the casing from the position shown in Figure 4, the lever 54 will be rocked, and as it bears on the abutment rod 50 of the angular xed portion 6, this rocking will permit the .casing 5 to be moved forwardly to true the grinding wheel, while on moving the rod 51 backwardly to the position shown the casing 5 .will be retracted from the wheel. This inward or truing motion may be effected by a pair of springs 60 one of which is shown in Figure 2. The outer end of each spring 60 is hooked over a pin 6| in a clip 62 secured as by a bolt 63 to the member 6, and its inner-end is engaged with the end portion of a U-shaped link 64, the opposite end of which is pivoted at 65 to an arm 66 secured to a rock shaft 61. When the rock shaft is in the angular position shown in Figure 2, the corresponding spring 60 is under tension and presses the casing 5 as far as it is permitted by the angular position of the lever 54 toward the grinding wheel. By turning the shaft 61 counterclockwise as viewed in Figure 2, 'the tension on the spring 60 may be released, the arm 66 being then turned away from its dead center position with relation to the line of pull of the spring 60.

, As shown in Figure 4, the inner end of the casthe work to be ground. This long gear 25 meshesy ing 5 is slidable through a packing ring 10 secured as by a retaining ring 1| to a fiange 12 on the wheel head or frame 3, and back from the inner edge of the casing 5 it is shown as provided with a transverse partition 13 forming with the outside wall of the casing a chamber 14 within which are positioned the truing devices. As shown, there are three truing'devices. Two Aof these devices 80 and 8| -are supported on rock arms 82 and 83, respectively, which are secured to the end portions of a pair of rock shafts 84 and 85, so that these truing devices are eccentric to these rock shafts, whereby as these shafts are 4 rocked the truing devices are caused to move transverse to the line of motion of the truing mechanism from and toward the wheel I. The third truing device 86 which may be employed to true the extreme edge of the wheel, as, for example, in truing it to grind U. S. standard threads, is carried by an arm 81 fixed to a rockable and axially movable shaft 88. All of these truing device carrying shafts extend through the casing wall 13, preferably through suitable stuifing or packing glands, so as to prevent the entrance of grit from the wheel and other'foreignA matter back of the partition 13 and into contact with the actuating mechanism by which the motions of the truing devices are produced. The motions of these three shafts for effecting the lateral motions of the truing devices relative to the line of motion of the casing 5 are produced by power, as shown, this being derived from a motor 90 secured to the rear face of the casing 5 above the angularly fixed member 6. This motor, as shown in Figures 3 and 4, carries on its armature shaft a spiral gear 9| which meshes with a spiral gear 92 on a vertical shaft 93. This shaft 93 carries a worm 94 (see Figure 3) which meshes with a worm wheel 95 on a cam shaft 96 (see Figures 3 and 5) carrying a cam 91. The cam 91 is provided with a cam groove 98 therein within which rides a follower 99 on a rock arm |00 (see Figures 6 and 10). 'I'he rock arm |00 which is fulcrumed on the fixed pin |0| is provided with a pair of spaced gear segments |02 and |03. The gear segment |02 meshes with teeth on a rack sleeve |04 secured to the rod 51,

so that, as the cam 91 is rotated, the rod 51 isv moved axially alternately in opposite directions to retract the truing mechanism from the grinding wheel and then permit it to approach the wheel under the action of the springs 60. The segment |03 meshes with rack teeth on a slide |05 (see Figures 6, 7 and 10) this slide being guided for its motion on a pair of fixed guide bars |06 and |01 mounted in fixed relation on the inside of the casing 5. The slide 05 has adjustably secured thereto a former cam |08 having a cam edge |09. This former cam may be secured at one end to the slide |05 as bya bolt ||0 and at its other end by a slot and bolt connection which permits adjustment of the steepness of the slope of the cam edge |09. Cooperating with this former cam edge |09 is a cam follower block ||5 supported at the end of an arm H6, rockably mounted at its opposite end on a hub ||1 (Figure 4) of a rock arm ||8 secured to the rock shaft 84. A screw abutment H60 (Figures 6 and 1) may be carried by the arm 6 in position to ride, when desired, on the slide 05 when the follower ||5 rides off from the former cam. The arm H8 and the arm ||6 are adjustably related angularly through an adjusting screw ||9 (Figures 2 and 6) threaded through the arm H9 and bearing against the arm |6. The arm i i8 is held is A , with the adjusting screw H8 in contact with the arm ||8 as by a spring-pressed plunger ||80. By adjustment of the angular position ofthe former cam |08 and the angular relationship between the arms ||8 and H6, therocking motion of the shaft 84 may be precisely controlled and correlated to the axial motion of the casing 5`so as to produce accurate control of the contour of the wheel side face trued by the truing device 80 which is carried by the rock arm 82 Afixed to the shaft 84.

From the shaft 84 operative connections are provided to control the rocking motion of the rock shaft 85 which carries the truing device 8|. As shown best in Figures 4, 5 and 8, these connections comprise an arm |20 carried by the shaft 84 and an arm |2| carried by the shaft 851. One of these arms, as the arm |2| shown in Figure 8, is slotted as at |22 for the adjustment toward and from the axis of the shaft 85 of a pivot |23 of a link |24, the opposite end of which is pivoted as at |25 to the arm |20. A spring |26 connecting these pivots at the ends of the link |24 take up any lost motion between the arms |20 and 2| so that the angular position of the shaft 85 is accurately but adjustably controlled by the angular position of the shaft 84. Thus the side truing devices 80 and 8| are accurately controlled, and, if desired, differently,I so that the wheel may be trued with its side faces having the desired angular relationship to each other. The shape of the cam `edge |09 of the former cam may also be varied as desired to play its part in thev determination of the wheel contour truedlby the side truing devices,

The third truing device 86 which trues off the extreme edge of the grinding wheel, as, for example, when it is desired to grind U. S. standard threads, is shown as actuated from the cam shaft 96. Referring particularly to Figures 5 and 9, the forward end of the cam shaft 86 is shown as providedwith an edge cam |30, against which islpressed, as by a spring |32, a cam follower |3| carried by an arm |33 fixed as by a pin |34 transversely to the shaft 88. The opposite end of the arm |33 carries a cam follower |35 which rests against the end face of la cam member |36. This end face is inclined so that, as the arm |33 is rocked by the edge cam |30 about the axis of the shaft 88, it also gives the shaft 88 an axial motion, the follower |35 being held up against the cam |36 as by a coiled spring |31 surrounding the shaft 88 and reacting between the lever |33 and a bearing member |340 in which the shaft 88 is journaled. The amount of this axial motion may be determined by adjusting the cam |36 angularly about its axis and the limits of this motion are determined by adjusting the cam |36 axially. The means for effecting these adjustments is shown best in Figure 11. The cam |36 is provided with a central shaft portion |31 flattened at, its outer endas at |38 and engaging a slot |39 in a diskA |40, so that, as thedisk |40 is adjusted angularly, it turns the cam |36 therewith. The vdisk |40 is provided with an arcuate slot |4| therethrough within which rides a tightening screw |42 provided with a head |43 which may be clamped against the outer face of the disk |40. This clamps this disk against the outer face of a rectangular plate |45 which in turn bears against the outer face of a bearing |46 in which is threaded a `sleeve |48. 'I'his sleeve |48 is provided with key projections 50 whichengage correspondingly shaped slots extending from a central opening |5| of the plate through which the portion |38 extends into the slot |38 ofthe disk |40. The plate |45 may be fixed in adjusted angular position by the adjusting screw |55 frame member |46 axially, moving the cam |36 axially with it, while the cam |36 may be adjusted angularly by rotating the disk |40 to the desired extent. Adjustments having been made, the cam |36 is fixed in its adjusted position by tightening the bolts |42 and |55. Thus a very accurate adjustment of the motion of the truing device 86 may be had, its axial motion being superimposed on the axial motion derived by the motion of the casing 5, or, if the parts are so timed, the entire operative control of this third truing device is produced by the cam |30 and the cam |36.

The cam shaft 96 may also be employed to actuate certain controls for the various machine operations. For example, in Figure 5; a sleeve 200 may be fixed thereto, this sleeve having hub portions 20| and 202 of different sizes to which may b secured in any suitable manner the co1- lars 203`and 204,`respectively. These collars, as well as a flange 205 shown as integral with the sleeve 200, may be arranged as cams for controlling three electric switches 206, 201 and 208 shown in dotted lines in Figure 4. These switches and cam actuators may be so arranged that, after the motor 90 has been started by a suitable switch (not shown) at the end o-f a traverse between the wheel and the work, the first portion oi the motion ofthe shaft 96 actuates one of these electric switches to slow down the speed of the grinding wheel the normal cutting speed of which is too fast for the best effects in truing. Another of these switches may be actuated just prior to the completion of asingle revolution of the cam shaft 96 to start the reverse traverse drive between the wheel and the work, and, as soon as this has been established and the cam `shaft 86 completes one revolution, the third switch is actuated to sto-p the truing motor 80.

These parts have not been shown in detail herein nor specifically described, since per se they form no part of the present invention.

In operation of the machine, the motor 90 is started at the desired time, as at the end of a traverse between the wheel and the work, and through its driving connections it rotates the cam shaft 96 and its cam 91 through a single revolution and is then automatically stopped by actuation of one of the cam collars 203 or 204, or the cam fiange 205, the speed of rotation of the grinding wheel being slowed at or near the start of the cycle and returned to normal at or near the end of the cycle. This control action forms per se no part of the present invention, being set forth more in detail and claimed in the Flanders application Serial No. 94,903, filed August 8, 1936, for Grinding machine. Rotation of the cam 91 causes a complete oscillation of the rocker arm |00, which acts to impart a complete reciprocation of the thrust rod 51 causing the entire truing mechanism with its casing to move toward and then from the grinding wheel edge,

At the lower. ||5. This rocks the arms ||6 and ||8 and the rock shaft 84 and through it the rock shaft 85 to impart lateral components of motion to the truing tools 80 and 8| properly co-related to the 'longitudinal motion component provided bythe in and out motion of the entire mechanism, to true the side faces of the grinding Wheel to the desired contours. At the same timey the cam |30,

`with its motion modified by the cam |36, and also by the in and out motion of the entire truing mechanism, produces the truing and return stroke of the end truing device 86. Periodic turning of cordance with its decreasing diameter as it wears and is trued. The casing 5 of the truing mechanism is shown as provided with a scale 220 indicating in connection with a fixed part of the -machine, such as the edge of the mating stationary frame portion, the diameter in inches of the wheel for a definite position of the casing in its cycle with respect to the grinding operation. Since the truing devices are normally held just out of contact with the grinding wheel for the major portion of the time of operation, this retracted position' of the casing may Well be that chosen for the correct indication. Thus, when the truing mechanism is retracted, the scale may indicate the true diameter of the wheel and not the actual distance of the truing tools from the axis of the wheel.

In connection with this indicator, is a table 22| located in convenient sighting position. for the operator of the machine, and. shown detached in Figure 13, this table showing for diierent wheel speeds and wheel diameters, the corresponding approximate surface speed in feet per minute. 'Ihe wheel driving motor, indicated diagrammatieally at 225, is a variable speed motor, as shown being a direct current shunt motor with a eld 226 variable by means of a rheostat at 221. By decreasing the field strength, as by interposing more of the resistance from the rheostat in the eld circuit in the well understood manner, the motor speed may be increased to compensate for decreasing wheel diameter due to wear and tru.- ing. The rheostat' may have a' hand control means, shown at 228 in Figure 12, with indications thereon of the revolutions per minute of the grinding wheel. For any desired cutting surface speed in feet per minute, it isthus easy for the operator to adjust the-rheostat control 228 in accordance with the table 22| for tlre desired surface speed in accordance with the wheel diameter as indicated by the scaie 220 when the truing mechanism is in any desired position of its cycle such, for example, as its retracted position. Of course, any other type of variable speed motor might be .employed with its properly marked speed control mechanism in place of the rheostat control of the eld strength of a direct current motor.

From the foregoing description lof an embodiment of an invention shown by way of example and not of limitation, it should be evident to those skilled in the art that various changes and modifications may be made without departing from the spirit or scope of this invention as defined by the appended claims.

.vice supporting portion angularly adjustable about an axis lying in the line of motion of said carriage, a truing device carried by said portion for motion laterally of said axis, means for moving said carriage toward and from the wheel,

means for moving said truing device relative to said carriage laterally of said axis, and connections from said carriage-moving means to said truing device moving means including a device correlating their relative motions to determine the resultant path of motion of said truing device relative to the wheel having components of said carriage motion and the motion of said device relative to said carriage to thereby determine the contour of the wheel face trued.

2. In combination, a truing mechanism comprising a carriage, means supporting said carriage for motion toward and from a grinding wheel to be trued, said carriage including a pair of parts one of which is angularly fixed and the other of which is angularly adjustable relative to said xed part about an axis lying in the line of motion of said carriage, a truing device carried by said angularly adjustable part, a lever fulcrumed on said xed part, an abutment on which another portion of said lever may engage, means yieldingly holding said lever in engagement with said abutment, and means for moving said lever to thereby move said carriage.

3. In combination, a truing mechanism comprising a carriage, means supporting said carriage for motion toward and from a grinding wheel to be trued, said carriage including a pair of parts one of which is angularly xed and the other of which is angularly adjustable relative to said fixed part about an axis lying in the line of motion of said carriage, a rod coaxial with the center of such angular adjustment, a truing device carried by said angularly adjustable part, a lever fulcrumed on said xed part and having a portion in alinement with said rod, an abutment on which another portion of said lever may engage, means yieldingly holdingA said lever in engagement with said rod and said abutment, means for moving said device, and means for moving said rod axially to thereby move said carriage.

4. In -combination, a truing mechanism comprising a carriage, means supporting said carriage for motion toward and from a grinding wheel to be trued, said carriage including a pair of parts one of which is angularly fixed and the other of which is angularly adjustable relative to said xed part about an axis lying in the line of motion of said carriage, a truing device carried by said angularly adjustable part for motion transverse to said line of motion, a lever fulcrumed on said fixed part, an abutment on which another portion of said lever may engage, means yieldingly holding said lever in engagement with said abutment, means for moving said device, and means for moving said lever to thereby move said carriage.

5. In combination, a wheel-truing mechanism comprising a carriage, means supporting said carriage for motion toward and from a grinding wheel to be trued, a rock shaft journaled in said carriage with its axis parallel to the line of motion thereof, an arm carried by said rock shaft, a truing device carried by said arm for truing a face of said wheel. means for rocking said shaft to impart a component iof motion to. said device laterally oi the line of motion of said carriage,

` means for producing said motion of said carcomprising a rock shaft, a truing device eccen trically connected to said rock shaft, an arm carriedby said rock shaft, a cam follower carried by said arm, a reciprocable member, an edge cam carried by said member, means holding said follower against said cam, and means actuable to reciprocate said member to thereby impart a wheel-truing motion to said device.

'7. In combination, a truing mechanism comprising a carriage, means supporting said carriage for motion toward and from a grinding wheel to be trued, said carriage including a pair of parts one of which is angularly xed and the other of which is angularly adjustable relative to said fixed part about an axis lying in the line oi motion of said carriage, a truing device carried by said angularly adjustable part, a lever fulcrumed on said fixed part, an abutment on whichI another portion of said lever may engage, means yieldingly holding said lever in engagement with said abutment, means for moving said lever to thereby move said carriage, and means for adjusting the position of said abutment to compensate for wheel wear and truing.

8. In combination, a truing mechanism comprising a carriage, means supporting said carriage for motion towardl and from a grinding wheel to be trued, a wheel truing device carried by said carriage, a lever fulcrumed on said carriage, an abutment carried by said supporting means on which another portion of said lever may engage, means yieldingly holding said lever in engagement with said abutment, and means for moving said lever to thereby move' said carriage.

9. In combination, a truing mechanism comprising acarriage, means supporting said car:- riage for motion toward and from a grinding wheel to be trued, a. wheel truing device carried by said carriage, a lever fulcrumed on said carriage, an abutment carried by said supporting means on which another portion of said lever may engage, means yieldingly holding said lever in en-4 gagement with said abutment, means for moving said lever to thereby move said carriage, and means for adjusting the position of said abutment with relation to said supporting means.

l0. In combination, a wheel truing mechanism comprising a carriage,l means supporting said carriage for rectilinear motion toward and from a `grinding wheel to be trued, a pair of parallel rock shafts journaled in said carriage with their axes in the direction of said carriage motion, connections between said rock shafts for producing a simultaneous rocking thereof, a truing device eccentrically carried by each shaft for truing faces of said Wheel, mechanisml for rocking one of said shafts, means carried by said carriage and operatively engaging said supporting means for producing said motion of said carriage, and means actuating said producing means and said shaft-rocking means simultaneously co-related to produce desired traversing paths of said devices relative to said wheel faces.

RALPH E. FLANDERS. LEE M. DAVIS. 

